WO2014141234A1

WO2014141234A1 - System for measuring urine volume and flow rate

Info

Publication number: WO2014141234A1
Application number: PCT/IL2014/050211
Authority: WO
Inventors: Zeev Cohen
Original assignee: Flometrica Ltd.
Priority date: 2013-03-13
Filing date: 2014-03-03
Publication date: 2014-09-18

Abstract

The invention relates to a system for measuring a volume and flow rate of urine, which comprises : (A) a vessel which comprises : (a) a first wall; (b) a bottom capacitor and plurality of ring capacitors, each of said capacitors comprises an external plate, a dielectric material and an internal plate, wherein the area of said internal plate is determined by the volume of urine within the vessel, and by a possible slant orientation of the vessel; (c) a common electrode within the vessel, which is in contact with urine! (B) a data collection circuit, which comprises : (d) a capacitance depending oscillator: (f) a multiplexer for connecting one at a time one of said capacitors to said oscillator; and (g) a processor for controlling said multiplexer to sequentially select one at a time another capacitor from said capacitors, for determining a respective oscillator frequency resulting from each of said selections, and for storing within a memory for each such selection a respective frequency and time stamp, all said storage forms a raw data; and said memory for storing said raw data.

Description

SYSTEM FOR MEASURING URINE VOLUME AND FLOW RATE Field of the Invention

The present invention relates in general to devices and methods for measuring volume and rate of flow of fluid. More specifically, the invention relates to a device and method for measuring volume and rate of flow of urine.

Background of the Invention

Lower Urinary Tract Symptoms (LUTS) are a common problem affecting approximately 50% of men over the age of 40. Filling or irritative symptoms include: interruption of urination frequency, urination urgency, Dysuria and Nocturia. Voiding or obstructive symptoms include: a poor stream, hesitancy, terminal dribbling, incomplete voiding and overflow incontinence. Diagnostics of the above symptoms is achieved by referring the patients to undertake a urine flow test. Using the currently available testing method, the patient urinates into a urine flow meter test machine. The results serve as a preliminary diagnostic tool for the physicians.

WO2007/111001 provides an apparatus including: a container that receives urine! and a urine amount measuring device that measures the weight of the urine received by the container! wherein the urine amount measuring device has: a mounting plate, which is a plate on which the container is mounted; a measuring portion that measures the weight of the container mounted on the mounting plate multiple times at given time intervals! and an output portion that outputs a result of the measurement performed by the measuring portion, and the apparatus has a fixing structure that is situated in at least a bottom portion of the container and a mounting face of the mounting plate and that detachably fixes the container on the mounting plate.

The existing urine measurement devices generally possess a plurality of inherent pitfalls: (i) Conventional testing is not done at physiological conditions;

(ii) The measurement devices are not hygienic since it is practically impossible to urinate only to the container and urine contaminates the measuring device. These devices require cleaning and skilled maintenance to operate properly.

(iii) Some devices have a removable receptacle without sensors that are in sensing vicinity with the urine or other fluidic body sample! these devices do not address the problem of contamination of other parts of the measuring device nor provide accurate urine measurements.

(iv) Other devices operate on the principle of creating air pressure changes in a locked chamber due to urine administered to the chamber. These devices are very limited in accuracy and susceptible to temperature changes created by the urine, Atmospheric pressure, and the need to keep the air chamber 100% sealed for the measurement to take place accurately.

Current devices for measuring urine measurements in general are cumbersome, or employ rather inaccurate methodologies for urine measurement. The equipment used requires cleaning and maintenance and are typically operated by professional trained staff, therefore they are normally available only in hospitals or clinics. It is therefore highly desired to provide a system which is of low cost, is simple to fully operate by the typical patient at his home, and wherein most of it is disposable.

WO 2011/010311 by same applicants as of the present invention discloses a urine collection and flow analyzing system. The urine collection system mainly comprises of a urine collection vessel, and a portable urine flow data collection device (hereinafter, USB device). The system of WO 2011/010311 is particularly adapted to measure the urine volume, and its flow rate. The system is also adapted to record and analyze various parameters and details with respect to the urine collections over time, such as to record times of urine collections, to provide various graphs with respect to the progression of the urine collections, etc. The urine collection vessel of WO 2011/010311 comprises in general one or more sensors for sensing the level of urine within the vessel, and a sensor port for enabling connection of a portable USB device. The portable USB device has two ports, a sensor port by which the device is connected to the sensor port of the vessel during the urine collection, and a USB port for transferring data to a computer after the termination of the urine collection. The USB device comprises a processor for communicating with a sensor within the vessel. In a preferable embodiment of WO 2011/010311, the urine measuring sensor is a capacitive sensor, whose capacity is determined by the level of urine within the vessel. More specifically, the collecting vessel is externally comprises a metal plate which forms a first plate of a capacitor, while the urine itself forms the second plate of the capacitor. The dielectric material is formed by the collecting vessel material. The figure of the urine vessel determines the ratio between urine volume and the contact area between the urine and the vessel, and in other words, the contact surface area is the capacitor second plate. Therefore, an increase of the amount of urine within the vessel, results in an increase of the capacitance of the capacitive sensor.

The portable USB device of WO 2011/010311 comprises a capacitive oscillator. Upon connection of the USB device, the capacitive sensor is connected within said oscillator, and serves as the capacitor of the oscillator. As noted, the capacitance of this capacitor varies as a function of the level of urine within the vessel. Therefore, during urine collection, the frequency of the oscillator varies as a function of the volume of the urine within the vessel. The rate of change of this level of urine actually defines the flow rate of the urine into the vessel. Therefore, the USB device of WO 2011/010311 enables determination of both the amount of urine and of the flow rate of urine into the vessel.

There are several drawbacks in the device of WO 2011/010311, as follows^

1. The device of WO 2011/010311 requires calibration before distribution into the market in order to compensate for production tolerances. The calibration procedure is expensive and cumbersome.

2. The device requires the vessel to be fully stationary during the urine collection, otherwise the procedure results in inaccuracies.

3. The device requires the urine collection to begin with a partially vessel filled with water (i.e., the bottom of the vessel must be covered with liquid).

4. The portable USB device has two separate ports, a first for connection to the vessel, and a second for connection to a computer upon completion of the collection.

It is therefore one object of the present invention to provide a system which overcomes all the above deficiencies of WO 2011/010311. More specifically, it is an object of the present invention to provide a urine collection system which does not require alignment before distribution to the market, which enables urine collection even when the vessel is not fully stationary, which does not require pre-filling of the vessel with water before the urine collection, and in which the portable USB port has only one common port for a respective connection both to the vessel during the urine collection, and to the computer after the urine collection.

It is still another object of the present invention to improve the patient compliance, measurement accuracy, the system manufacturability, and the system reliability, and to reduce the system costs. Other objects and advantages of the present invention will become apparent as the description proceeds.

Summary of the Invention

The invention relates to a system for measuring a volume and flow rate of urine, which comprises: (A) a vessel which comprises: (a) a first wall; (b) a bottom capacitor and plurality of ring capacitors, each of said capacitors comprises an external plate, a dielectric material and an internal plate, wherein the area of said internal plate is determined by the volume of urine within the vessel, and by a possible slant orientation of the vessel; (c) a common electrode within the vessel, which is in contact with urine! (B) a data collection circuit, which comprises: (d) a capacitance depending oscillator! (f) a multiplexer for connecting one at a time one of said capacitors to said oscillator! and (g) a processor for controlling said multiplexer to sequentially select one at a time another capacitor from said capacitors, for determining a respective oscillator frequency resulting from each of said selections, and for storing within a memory for each such selection a respective frequency and time stamp, all said storage forms a raw data! and

said memory for storing said raw data.

Preferably, each of said ring capacitors comprises a first plate which is made of a conductive foil that surrounds a peripheral portion of said first wall, a dielectric material made by the material of said wall, and a second plate which is formed by the contact area of the urine with said first wall opposite said ring capacitor foil respectively, and wherein said bottom capacitor comprises a first plate which is made of a conductive foil which is disposed at a bottom of said first wall, a dielectric material made by the material of said wall, and a second plate which is formed by the contact area of the urine with said first wall opposite said bottom capacitor foil. Preferably, each of said conductive foils is disposed on the external surface of said first wall.

Preferably, each of said ring capacitors is separated from adjacent one or more capacitors by a narrow gap respectively.

Preferably, each of said narrow gaps has an inclined shape.

Preferably, each of said ring capacitors comprises a first plate which is made of a conductive foil that is disposed on an internal surface of said first wall, a dielectric material made by the material of urine, and a second plate which is provided over a post at the center of the vessel, and wherein said bottom capacitor comprises a first plate which is made of a conductive foil which is disposed at the bottom of said first wall, a dielectric material made by the material of said wall, and a second plate which is formed by the contact area of the urine with said first wall opposite said bottom capacitor foil.

Preferably, said multiplexer, oscillator, processor, and memory are provided within a USB device which is connectable to said vessel via a port, and which is connectable to a computer via a USB port.

Preferably, the USB device is connectable to said vessel via the same USB port which is used for connecting the USB device to the computer.

Preferably, said data collection circuit is included within the vessel, and wherein the content of said memory is transferred to the computer wirelessly.

Preferably, the oscillator frequency is inversely proportional to the capacitance of each of said capacitors respectively.

Preferably, said vessel further comprises a funnel for directing any additional urine to the bottom of the vessel. Preferably, the funnel, internal surface of said wall, or both are coated with a hydrophobic material.

Preferably, said common electrode is placed along the height of the internal surface of said first wall.

Preferably, the vessel further comprises a second peripheral wall, and wherein said peripheral wall is covered by a shielding foil to shield the vessel from the body effects of the user.

Preferably, the vessel is cylindrical. In another alternative, the vessel has a truncated cone shape.

In another embodiment, the system is used for providing a urination and drinking diary which records the time of urination along with urination volume (and optionally flow rate) and the time of liquid intake along with liquid intake volume. For recording liquid intake the embodiment further comprises buttons for inputting a drinking volume, and wherein the system records each time said drinking and a corresponding time stamp.

In another embodiment of urination and drinking diary the system may use two cups! one for urination and one for drinking. Each cup will have its own electronic measuring and recording device or a single device will be shared between the cups.

Preferably, the oscillator is replaced by a charging circuit, and wherein the measured urine volume is determined by measuring the period or voltage and rate of charging rather than the frequency determination. Preferably, each of said foils is disposed at the internal surface of said first wall.

In an embodiment of the invention, the system may not comprise a bottom capacitor.

Preferably, each of said ring capacitors comprises a first plate which is made of a conductive foil and a second plate which is also made of a conductive foil placed at a small distance apart, where the urine is the dielectric material.

Preferably, the plate structure is located as a post at the center of the vessel.

The invention also relates to a method for measuring a volume and flow rate of urine, which comprises^ (a) providing a vessel; (b) providing at the vessel a bottom capacitor and plurality of ring capacitors, each of said capacitors comprises an external plate, a dielectric material and an internal plate, wherein the area of said internal plate is determined by the volume of urine within the vessel, and by a possible slant orientation of the vessel; (c) providing a capacitance depending oscillator; (d) while giving urine into said vessel, selecting sequentially one at a time one of said capacitors, and connecting the same to said oscillator! and (e) during each such selection, recording respectively within a memory the temporal frequency and time stamp of said oscillator; and (f) at the end of said urine giving, analyzing said stored frequencies and respective time stamps in memory to determine the temporal urine volumes and urine flow rate.

Preferably, said analysis stage comprises^ (a) grouping the plurality recorded frequencies and time stamps respectively according to the respective capacitors! (b) determining the progression of the urine flow starting from said bottom capacitor and higher to a highest influenced capacitor from among said ring capacitors, based on said frequencies and time stamps corresponding to each capacitor! and (c) determining a total urine volume based on the highest influenced capacitor, and possibly also based on a calculated slant of the vessel; calculating temporal flow rates during said progression based on frequency variations during said progression.

Preferably, the flow rate linearly relates to the rate of

Preferably, said bottom capacitor is used to determine the time of beginning of the procedure, and the volume and flow rate of urine at the beginning of the procedure until this capacitor is fully covered.

Preferably, at the beginning of the procedure, when said bottom capacitor is not fully covered with urine, the urine volume is determined by an integration of the volume, as determined with respect to said bottom capacitor, and with respect to one or more of the ring capacitors.

Preferably, one or more gaps between capacitors respectively are taken into account in the analysis.

Preferably, the width of each ring capacitor is selected to relate to a predetermined urine volume, and knowledge of this predetermined volume is used in the analysis.

Brief Description of the Drawings

In the drawings:

Fig. la shows the urine collection system, according to a first embodiment of the present invention!

Fig. lb is a cross section view of the system of Fig. la!

Fig. 2a shows a basic structure of the USB device according to an embodiment of the invention!

Fig. 2b shows an alternative to the embodiment of Fig. 2a! Fig. 2c shows an alternative to the embodiment of Figs. 2a and 2b, in which the components of the USB device are embedded within the vessel, and in which the collected data is transmitted to a computer wirelessly; Figs. 3a^_3c show three exemplary situations with respect to the accumulation of urine within the vessel;

Fig. 4 shows the manner of forming the capacitors within the internal cup of vessel!

Fig. 5 shows a typical 555 circuit which is used in an embodiment of the invention!

Fig. 6 is a flow chart generally describing the steps that are performed upon completion of one or more urine giving procedures;

Fig. 7 is a flow chart generally describing the temporal volume and flow rate calculations that are performed by the computer after the data collection; and

Figs. 8a and 8b show still another embodiment of the invention, in which the gaps between the rings have a saw-tooth shape.

Detailed Description of Preferred Embodiments

The present invention relates to a urine collection and analysis system, which mainly comprises a urine collection vessel, and a portable urine flow data collection device (hereinafter, USB device), in similarity to WO 2011/010311 which was briefly discussed above. As will become apparent, the urine collection and analysis system of the present invention is substantially different from the system of WO 2011/010311, and includes substantial improvements that will become apparent, as the description proceeds. Hereinafter, the system of the invention will be briefly referred to as a "urine collection system".

Fig. la shows the urine collection system 10, according to a first embodiment of the present invention. Fig. lb is a cross section view of the system of Fig. la. The urine collection system mainly comprises of a urine collection vessel 11, and a portable USB device 12. The USB device 12 is shown connected to the urine collection vessel 11. While in operation, the urine collection vessel receives urine from a patient, and the USB device continuously senses and records parameters, that can be used later on for the determination of various factors, such as the volume and flow rate variation of the received urine.

Vessel 11, which is preferably made to be disposable (i.e., preferably to no more than 3 urine giving measurements), comprises a funnel 22 having bottom openings 13, internal wall 14, and external wall 15. Walls 14 and 15 are spaced apart from one another by a distance of several millimeters (e.g., 4mm). The hollow space between the internal wall 14 and the external wall 15 contains, for example, air. Hereinafter, the essentially cylindrical (or somewhat truncated cone) structure which is defined by the internal wall 14 will be referred to as the "internal cup", and similarly, the structure which is defined by the external wall 15 will be referred to as "external cup". It should be noted that the "internal cup" has most preferably a cylindrical shape, as a cylindrical structure provides most accurate results (the reasons for this determination will be discussed later). It should be noted, however, that an internal cup having a truncated cone shape (or another shape) may also be used, but when a truncated cone is used, it is preferable that its shape will be close to a cylindrical shape, as in that case the inaccuracies are minimized. Typically, it is somewhat more expensive to manufacture a cylindrical-shape cup than a cup having a truncated cone shape, and for this reason, said latter shape may be preferred in some cases.

Urine which is received at the vessel 11, spills through openings 13 at the bottom of funnel 22, and accumulates within spaces 17 and 18 of vessel 11. More specifically, based on the connected vessels law, the urine accumulates both within the space 17 (i.e., between the external surface of funnel 22, and the internal surface of internal wall 14), and within the space 18 within funnel 22. The parameters relating to the temporal volume and flow rate of the urine are measured and recorded by USB device 12. The basic structure of the USB device 12 is shown in Fig. 2a. USB device 12 comprises an oscillator 50, whose oscillation frequency depends each time on one of the capacitors Ci - C5 (that will be discussed later on), as selected by multiplexer 51. The selection of the active port of multiplexer 51, and therefore also of the active capacitor from the group CrCs is controlled by processor 55. The selection of the active port of multiplexer 51 may be sequentially and periodically switched by processor 55 (for example, every 0.1 second), such that each time the frequency of oscillator 50 is determined by another capacitor from the group Ci - C5. As will be discussed in more detail hereinafter, the individual temporal capacity of each of the capacitors Ci - C5 depends on the volume of the urine within the vessel 10. As the urine accumulates within the vessel, the capacitance of one or more of the capacitors Ci - C5 gradually varies, therefore causing respective variations of the frequencies of oscillation. Processor 55 continuously monitors the frequency of oscillator 50 (as varies in view of the urine accumulation and in view of the sequential selection of an individual capacitor from within the capacitors Ci - C5), and records within memory 56 (which can be an external component to the processor or embedded within the processor) the respective temporal oscillation frequencies. It should be noted that the number of capacitors may vary, and the 4 capacitors discussed herein is given for the sake of explanation. Also, for the sake of design convenience or to reduce costs, and as will be further discussed hereinafter with respect to capacitors Ci and C5, in some embodiments two or more capacitors may be combined to a single capacitor (by electrical short) to reduce the number of capacitors that are required for measurement. In this case the sensitivity will be somewhat compromised. The memory 56 stores said frequencies as "raw data" until a later time. Upon completion of the urine accumulation, the USB device 12 is disconnected from the vessel 10, and is connected to a computer via the same USB port 61. Preferably, a USB port 3.0 having 9 line connections is used for this purpose, enabling the use of a same USB port both for the connection of the USB device to the vessel, and for the later connection of the USB port to a computer. A dedicated program within the computer downloads the raw data from memory 56, and performs a volume and flow rate analysis based on said raw data.

Fig. 4 shows the manner of forming the capacitors within the internal cup of vessel 10. The capacitors CrCs are formed in the vessel 10. According to the present invention, capacitors C2^_C5 are plate capacitors, wherein each of said capacitors comprises^ (a) a first capacitor plate formed by a metal ring 58 which surrounds the external surface of the internal wall 14; (b) a dielectric material which is formed by the material of the wall 145 and (c) a second capacitor plate which is formed by the urine liquid itself, or more particularly, by the contact area of the urine with the internal surface of wall 14. Similarly, capacitor Ci is a plate capacitors, which comprises^ (a) a first capacitor plate formed by a metal circular plate 64 which is attached to the external surface of the bottom of internal wall 14; (b) a dielectric material which is formed by the material of the bottom of wall 14; and (c) a second capacitor plate which is formed by the urine liquid itself, or more particularly, by the contact area of the urine with the internal surface of the bottom of wall 14. The first plate of each of the capacitors CrCs is connected to the USB port via electrodes 66a-66e respectively. The electrode 76 of the second plate of each of the capacitors CrCe is provided on a strip 70 that goes down along a first side of the internal surface of wall 14, through the bottom, and continues up along a second side which is opposite to said first side of the internal surface of wall 14. This electrode 76 is common to all said capacitors CrCe. It should be noted that for the sake of convenience the term "plate" is used to describe the ring capacitor elements, even though these elements have a curved ring shape in cross section or rings having edges of a saw-tooth shape (therefore also the gaps between the edges have a saw tooth shape - this will be discussed in more details below). As shown, there are narrow gaps 69 between any two adjacent first plate rings 58, ensuring that there is no contact between adjacent rings, therefore ensuring that each ring relates to another capacitor. As noted, the gap can be horizontal or in saw-tooth shape. Also, there is no contact between the lowest ring 58a, and the bottom circular plate 64.

The following equation defines the capacitance of a plate capacitor:

_ £₀s_RA

L^~ D

Wherein:

ε₀ = 8.854e^~12 - is the vacuum dielectric constant (similar to the air dielectric constant);

E_R - is the material dielectric constant - in the present invention E_R is the dielectric constant of the material of wall 14;

A - is the surface area of the capacitor plate. With respect to the present invention, for example, if the urine level is above the top of the first ring (i.e., above the gap 69b), the surface area A relating to capacitor C2 is the area of ring 58a. If, however, the level of the urine is below the top level of ring 58a, the surface area A is the effective area of the contact between the urine liquid and the internal surface of wall 14, opposite to ring 58a.

While urine accumulates within the vessel, and depending on the level of the urine, the individual capacitance one or more of the capacitors may be gradually affected by the urine. Figs. 3a-3c show several typical situations that may occur and affect the respective capacitor values, as follows:

a. Fig. 3a shows a situation where the level of urine is about half of the width of ring 58a, indicated as hi. In this case, the effective area A for calculating the capacitance of C2 (assuming that the internal cup is purely cylindrical) is: 2πτΚγ (r is the radius of the cup). The effective area for calculating the area A of capacitor Ci (i.e., the circular bottom capacitor) is the entire area of the bottom of the internal cup, i.e., A = πτ². Since the system measures the capacitance, it can deduct the effective area, and hence the volume. b. Fig. 3b shows a situation similar to the case of Fig. 3a, however when the vessel is slightly slanted. The dotted line 73 indicates the upper level of the urine which would take place should the vessel would be perfectly leveled as in Fig. 3a (this line is parallel to the bottom). Clearly, when the cup is slanted, the upper surface of the urine remained leveled (i.e., horizontal). It can be seen that due to the slant of the vessel, the contact area of the urine with the internal surface of wall 14 at the left side of the vessel increases due to additional height x, however, at the right side the contact area decreases due to the slant by exactly same decrease of height x. These two heights are the same when the internal cup has a cylinder shape. Therefore, when the internal cup is cylindrical the "loss" of contact area at the right which occurs due to the slant of the cup is compensated at the left of the cup by an additional contact area of exactly the same size. This phenomenon shows that the invention is insensitive to the slanting of the cap when the internal cup has a cylindrical shape. If, however, the shape of the internal cup somewhat diverges from the cylindrical shape towards a conical shape, the two area differences x at the right and left are not exactly the same. However, even in such a case a compensation for the inaccuracy which evolves from said difference can be made. c. Fig. 3c shows a slanted vessel situation similar to the case of Fig.

3b, however, when the vessel just begins to accumulate urine. In that case, the bottom plate is not fully covered with urine, the effective area is smaller than the full area of the bottom, and the capacitance of Ci is affected accordingly by the effective contact area with the bottom of the cup. In this case, the relation between the contact area of the urine with the internal surface of wall 14 and the volume of the urine is not proportional (as opposed to the case when the bottom is fully covered) hence the bottom plate reading with respect to area m is integrated with the contact area u of the urine with the left side of ring capacitor C2 to evaluate the urine volume.

The oscillator 50 of Fig. 2a varies its frequency depending on the capacitor which is presently connected by multiplexer 51, and on the temporal value of the capacitor which is connected. As noted, the value of the capacitor depends on the contact area of the urine with the internal surface of internal wall 14. Therefore, during the urine accumulation, the capacitance of one or more of the capacitors C1-C5 changes, and the frequency of oscillator 50 changes respectively.

In one embodiment of the invention, the oscillator is based on the common integrated circuit 555. Fig. 5 shows a typical 555 circuit. The capacitor Ci in the circuit of Fig. 5 is the capacitor which determines the frequency of the oscillator, and this is actually one of the capacitors CrCs of the invention. The equation for determining the frequency of the circuit is^

1.44

(J¾ + 2fl₂)C

As becomes apparent, as the urine accumulates and affects the capacitance of one or more of the capacitors, the value of the respective capacitor increases, causing decrease of the frequency of the oscillator. Furthermore, it can be seen that the frequency not only inversely dependent on the capacitor, but the relation between them is also linear.

The embodiment of Fig. 2a shows 5 capacitors Ci - C5. This requires use of 5 electrodes of the USB port 61, as well as use of a 5 -port multiplexer 51. In some cases it may be found advantageous to use a 4-port multiplexer, as well as to utilize only 4 lines of USB 61. Fig. 2b shows a solution to this problem. In that case, capacitors Ci and C5 are shortened such that they are fed in parallel to the multiplexer. This combination forms on one hand a single combined capacitor, however, this combined capacitor is in fact divided to two separate sensors relating to Ci and C5 respectively. These two sensors are mutual exclusive. At the beginning of operation, just after the patient gives urine, the capacitance of Ci varies, while the capacitance of C5 remains stable (as the volume level of the urine is still too low to affect it). On the other hand, later on, when the urine volume level increases and reaches the level of capacitance C5, the capacitance of C5 varies, while the capacitance of Ci remains stable, as the urine already covers the entire area of Ci and nothing with respect to this area is expected to change. Therefore, in such manner of operation and arrangement, the algorithm of processor 55 can easily determine any time whether the change in the capacitance within the combined capacitor is caused by the portion of Ci or by the portion of C5 within the combined capacitor (this is done by monitoring the stage of the urine giving).

It should also be noted that even when the cup is empty, there is some capacitance in each of the capacitors, due to parasitic capacitance contributors. One of said capacitance contributors is the strip 70. However, all said parasitic capacitance contributions are constant, and can be easily taken into account while processing the raw data. Furthermore, the accuracy of the results may be harmed if during the urination the urine stream will hit the side walls. For example, just at the beginning of urination it is expected that only the bottom capacitor Ci and the first capacitor from the bottom C2 will be affected. However, if during the urination the stream hits, for example, the upper portion of the wall, capacitance C₄ may be inappropriately be affected. For this reason, the invention uses the funnel 22, which ensures that the urine accumulation within the vessel begins from the bottom. Moreover, the surfaces of the funnel, as well as the internal surface of wall 14 are preferably coated with a hydrophobic material in order to prevent accumulation of individual urine drops along the funnel or upper sections of the wall, as such parasitic accumulation may cause inaccuracies to the measurement. Still other contributors for the inaccuracy are the gaps 69. In the gaps area there is no external plate (i.e., ring) that measures the capacitance formed by the urine. However, urine accumulated in the gaps affects in a non-linear manner the capacitance of the upper and lower rings adjacent to the gap and can be taken into account. Still another contributor for a possible inaccuracy may be a hand palm or body touch of the user on the external surface of external wall 15 of the vessel. The touch of the user on the cup may affect the capacitance of the capacitors. This issue is resolved by providing a shielding metal foil (not shown in the drawings) around the surface of wall 15 (internally or externally). The common electrode 70 is connected to said shielding metal-foil to further ensure that the hand touch will not affect the capacitance of any of the capacitors.

The flow rate is determined from the variation of the urine volume over time, which is in fact determined indirectly from the variations of the frequencies over time. More specifically, the flow rate linearly relates to the rate of _AtAtA^-

Preferably, the width of the ring is selected to represent a known volume of urine. For example, the width (height) of each of the rings may be chosen to match lOOcc of urine within the cup. There are two options for calibrating the system. In a first calibration option, the oscillator frequency for each individual ring capacitor with an empty vessel is recorded. Said recorded frequency is typically the maximal frequency for this capacitor. Then, the vessel is maximally filled with liquid to a level above the top of the highest ring 58d. This causes the capacities of all the capacitors CrCe respectively to increase to their maximal possible values, and to the oscillator frequencies corresponding to each of the capacitors to reach their minimal values respectively. Therefore, having knowledge for each capacitor of its respective maximal frequency which represents empty vessel, and of its minimal frequency which represents its full known volume (for example, lOOcc), it is possible to determine for any frequency in between these two extremes the respective volume, as the frequency varies proportionally relative to the change of volume. It has been found that in practice the rate of frequency change relative to volume change in all the capacitors is essentially identical in all the capacitors, therefore this rate of change as determined following the calibration for one of the capacitors may be applied also to the higher capacitors. This observation is applied in the second option of calibration which has been found to be more preferable both in terms of accuracy and in terms of convenience. According to the second option, the vessel is filled with urine to a level above the capacitor C2, and the rate of frequency change relative to volume is determined for said capacitor C2. This rate, as determined, is then applied to the other ring capacitors. As noted, it has been found that this calibration procedure is most accurate and convenient, and therefore preferable, for the following reasons^ (a) it does not require a performance of calibration procedure at the factory! (b) if the calibration is performed according to (a), the time until the actual use (in typical several months) may change the calibration and may cause inaccuracies; and (c) it is in fact performed during the procedure itself, and does not require any special procedure.

It should be noted that in order to obtain best calculation of the volume of the urine, it is advised that upon completion of the urine giving, the patient will put the vessel on a leveled stationary object, such that the "waves" on the upper surface of the vessel will extinguish, and the oscillator final frequency will be stabilized based on the final urine volume.

EXAMPLE 1

If it is known that the height of the first ring capacitor represents lOOcc in volume, and the two frequency extremes relating to this ring capacitor are 25KHz (for the empty case) and 18KHz for a full ring case, and while a frequency of 20KHz is measured, it can be easily concluded that the vessel contains lOOcc X 0.64 = 64cc of urine.

EXAMPLE 2

If each of the first and second ring capacitors represent lOOcc! the two extremes for the first capacitor are 25KHz and 18KHz respectively (as mentioned before), and for the second ring capacitor the two extremes are 30KHz and 25KHz respectively, and the following frequencies are measured: (a) with the first capacitor 18KHz, and with the second capacitor 28 KHz, the following conclusions can be made:

(a) The volume of urine in the cap is more than lOOcc, as the oscillator frequency with the first capacitor has reached its minimal value; and

(b) The volume within the second capacitor borders is: lOOcc Z O.35 = 35cc; and

(c) The total volume of urine within the vessel is 100cc+35cc = 135cc.

The bottom plate capacitor Ci is used particularly to measure small volumes, or when the cup is slanted. When the cup is slanted, the relative covered area of the lower plate, as well as the relative covered area of the first capacitor can provide the basis for calculating the exact amount of urine by applying simple geometry calculations.

Therefore, and following the above, the present invention provides means for calculating at any given moment the amount of urine volume within the vessel. Moreover, the rate of variation of the volume over time brings the urine flow rate.

It should also be noted that the use of plurality of rings (for example, 4 rings) compared to use of a single ring capacitor is advantageous. In the above examples, 4 ring capacitors are used, while each capacitor represents lOOcc. A measurement of a very small change of urine volume (for example lcc) is more sensitive when performed within a lOOcc ring capacitor, compared to the case when measuring the same very small change of urine volume of lcc within a 400cc ring capacitor (as would be the case when a single "ring" capacitor is used for the entire vessel). In the first case, a lcc change is 1% of the total volume for the ring capacitor, while in the latter case, same lcc represents 0.25% from the total volume for the ring (and in fact, it is also 0.25% from the entire volume of the vessel).

The embodiment of Figs. 3a-3c and 4 which has been discussed above may introduce some minor inaccuracies, as there is no urine measurement within the areas of gaps 69 (even though these inaccuracies may be estimated and taken into account). In still another embodiment shown in Figs. 8a and 8b, these relatively minor inaccuracies (uncertainties) due to said gaps 69 are very substantially reduced, almost diminished. In similarity to the embodiment of Figs 3a^_3c and 4, the cup of Figs. 8a and 8b comprises plurality of "ring" capacitors 158a to 158d. However, while the gaps 69b - 69d of said previous embodiment have been made substantially horizontal (i.e., parallel to the bottom of the cap), in the embodiment of Figs. 8a and 8b these gaps 169b- 169d are made in a substantially saw-tooth (inclined) shape. It has been found that this saw-tooth shape is very advantageous, as the urine is typically accumulated parallel to the bottom of the cup. In the previous embodiment (of Figs. 3a-3c and 4), when the top of the accumulated urine reaches a gap 69, there is some uncertainty where exactly within the gap the "top of the liquid level" has reached. This uncertainty depends on the width and circumference of gap 69 )in essence, on the surface area of the liquid within the gap), and particularly affects the measurement and calculation of the flow rate. The embodiment of Figs. 8a and 8b overcomes this uncertainty. As shown in Fig. 8b, when the urine level reaches a gap 169, no matter what exactly the urine level is, the volume and flow rate uncertainty measurements are affected by very narrow areas (i.e., the surface area of the liquid within the gap), each depending on the width of the gap 180a-180n, rather than on the full circumference of the gap, as is the case in said previous embodiment. Clearly, this uncertainty in Figs. 8a and 8b is much smaller relative to the uncertainty in the previous embodiment, and it is almost constant regardless of the cup tilt. Moreover, this very minor "uncertainty" is in fact substantially constant along the varied level of the accumulated urine, as no matter where exactly along the gap this level is located, the amount of "uncertainty" is substantially constant, and can be fully taken into account in the flow rate and volume measurement algorithms.

It should be noted that in all the embodiments discussed above, each of the rings may not be continuous along its full peripheral length, as long as separate portions of the ring are electrically connected.

Preferably, the batteries of the USB device are normally disconnected. The batteries are connected to the electronics of the USB device only upon connection of the device via the USB port to the vessel. Therefore, at the time of connection, the USB device becomes active, and the electronic circuitry await for the beginning of the process. The beginning of the urination is determined when the processor 55 senses a change in oscillator frequency due to a change in the capacitance of capacitor Ci. In another embodiment, and when a urine diary is used, the batteries are continuously connected to keep a real-time-clock running.

The system of the present invention does not require calibration prior to its operation. As noted above, for each of the capacitors, there are two extreme frequencies: (a) a higher frequency when the vessel at the respective level of ring is empty! and (b) a higher frequency when the vessel at the respective level of ring is full. For those ring capacitors which pass through said two extreme frequencies, i.e., initially it is empty and later on the level of urine becomes to be above the top level of the ring, these two extreme frequencies for this ring become known at the end of the procedure. Any frequency between these two extremes the oscillator goes through with respect to this ring capacitor can be retrospectively associated with a urine volume. This is done based on the knowledge of the maximal urine volume relating to each capacitor (e.g., lOOcc), and on the fact that the variation of the frequency singularly relates to the urine volume, as discussed above. This is particularly important for the determination of the flow rate, in which the variation of the frequency is important.

As also noted above, when the vessel is a cylinder the system of the invention is insensitive to the slanting of the vessel, as the contact area of the urine with the internal surface of wall 14 remains the same for all slant angles (this is discussed above with respect to Fig. 3b). This is correct also when the slant involves a cross-rings situation (the calculation algorithm take care of this fact). However, when the vessel has a somewhat truncated conical shape, the slant causes some inaccuracies, as the contact area somewhat changes. Fortunately, these inaccuracies can be significantly minimized by taking the exact shape of the truncated cone vessel into consideration within the calculation algorithm. Moreover, the algorithm may estimate the angle of slant via the behaviors and effects of the rings on the oscillations. The calculation algorithm can also easily take into consideration the inaccuracies that result due to the narrow gaps 69 between the different rings, narrow locations in which the capacity of the capacitors does not change even when the urine volume slightly changes. Fortunately, the effects of these gaps are minimal, and can be easily estimated by the calculation procedure.

Fig. 6 describes the steps that are performed upon completion of one or more urine giving procedures. It should be noted that when raw data relating to several procedures are stored within memory 56, said raw data is separated according to the various procedures. In step 550, the raw data is downloaded into the computer. In step 551, the data is grouped according to the respective capacitor. For example, all the frequency samples for capacitor Ci are grouped together, and similarly, the grouping is performed for all the other capacitors. In step 552 the analysis is performed.

Fig. 7 describes the temporal volume and flow rate calculations that are performed by the computer after the measurement. The procedure in general calculates temporal volume calculations in a manner as described above, and during each selected period the flow rate can be determined by wherein V is the volume and t is a selected period. During the period

(Ti represents the time when the plate of Ci becomes full), the system calculates temporal volumes based on Ci + C2 - steps 700 and 701 (in some rare cases, when the vessel slant is extreme, additional capacitors may be considered in step 700). When the capacitor plate of Ci becomes full - time duration T2, and assuming that the urine containing portion is cylindrical, the slant becomes almost insignificant for the temporal volume calculations, which may be based on capacitors C2 - C_n. When the process is found to be stable - step 703 (i.e., constant oscillations), the calculations may be terminated, as the flow rate becomes zero. At this stage, the total volume may be calculated as well.

The description as provided so far relates to peripheral capacitor rings that are provided on the external surface of wall 14. The structure of the vessel 11 may modified such that the ring capacitors are provided around a central post which is located at the center of the vessel. Moreover, while in the description so far the contact area of the urine with the wall 14 as well as the dielectric constant of the wall's material, were considered for the determination of the various capacitances, the vessel 11 of the invention may be modified such that the dielectric constant of the urine itself may be used for the determination of the respective capacitances, rather than the dielectric material of the wall. In an alternative embodiment, the ring plates may be disposed over the internal surface of the internal wall 14, rather than over the external surface of said wall.

The description as provided so far relates to an oscillator in which the oscillation frequency varies relative to the change of the capacitance of the various capacitors. In still another alternative, instead of an oscillator, a charging circuit may be used. In such a charging circuit, the charging period depends on the capacitance of the capacitor. Therefore, when a charging circuit is used as an alternative to the oscillator, the processor 55 determines the urine volume (which affects the capacitance) by measuring the period or voltage rather than the frequency as described so far. Furthermore, in all said alternatives the memory may either store frequency, period, voltage or capacitance values, all these parameters enable determination of the respected urine volume.

As also noted above, the recording of time (or time stamp - these terms are equivalent) within the memory is important, and the accuracy of the time is significant for the determination of volume and flow rate. In some cases the accuracy of the clock of the processor is sufficient for this purpose. In other cases, a dedicated clock circuit may be provided within the USB device to improve the accuracy of time measurement and for better timing the various operations.

As noted above, the invention provides a system for measuring volume and flow rate of urine in a simple and low cost manner. The system comprises within the disposable vessel very few components to keep it simple and inexpensive. The USB device comprises the electronics which is just required to accumulate the raw data. Therefore, the USB device is also very simple and inexpensive. The computer, in turn, comprises a more sophisticated software which downloads the raw data from the memory at the USB device, determines the urine volume and flow rate at any urine giving procedure, and furthermore, it can provide further analysis, and parameters relating to different procedures to the doctor.

In still another embodiment of the invention, a system for a urination diary is provided. The system has essentially the same structure as described above, however, this embodiment measures the urination volume, and does not necessarily require calculation of the urine flow rate (although in some embodiments also the flow rate is calculated).. The volume of urination is measured as describe for the first embodiment. In addition, the system comprises a real time clock. When the user gives urine into the vessel, the exact time is recorded in memory 56, together with the urine volume (and also flow rate in some embodiments) as measured. The user may use a same USB device with several vessels that are disposed each time, in order to make a long duration diary. Alternatively, a same vessel may be used several times, while the user is expected to clean the vessel after each use. In addition, the USB device which records the urination volumes and times may also include means for recording the amount and/or type of water or other liquids that the user drinks. The USB device includes one or more push-buttons on which the user pushes each time that he drinks. For example, the user may push the button once if he drinks 250cc of water, twice if he drinks 500cc, etc. The USB device, in turn, will record the amount of drinking water, as well as the respective times within the memory of the USB device as well. When required, the data from the memory of the USB device may be uploaded into a computer, and a urination diary, as well as a water-drinking diary may be prepared.

In still another embodiment, instead of inserting the drinking intake via push buttons indications, a separate cup (from the urine measuring cup) is used by the user to record the drinking intake. The drinking intake cup has a similar structure as the urine cup described above, and it automatically records the amount of liquid consumed from it by the user (i.e., the amount of drinking liquid consumed). The drinking cup may shares a single USB device with the urination cup or a separate USB/wireless interface. It should be noted that the funnel which is a part of the urine cup, is not essential within the drinking cup, and it may be eliminated.

In still another embodiment of present invention shown in Fig. 2c, the entire USB device, including the processor, oscillator multiplexer, and memory is embedded within the vessel itself. In this embodiment, there are no USB ports 61. Instead, upon completion of the operation, the data which is stored in memory 56 is transmitted to a computer or smartphone wirelessly via wireless unit 91.

While some embodiments of the invention have been described by way of illustration, it will be apparent that the invention can be carried out with many modifications variations and adaptations, and with the use of numerous equivalents or alternative solutions that are within the scope of persons skilled in the art, without departing from the spirit of the invention or exceeding the scope of the claims.

Claims

1. System for measuring a volume and flow rate of urine, which comprises:

A. a vessel which comprises^

a. a first wall;

b. a bottom capacitor and plurality of ring capacitors, each of said capacitors comprises an external plate, a dielectric material and an internal plate, wherein the area of said internal plate is determined by the volume of urine within the vessel, and by a possible slant orientation of the vessel;

c. a common electrode within the vessel, which is in contact with urine!

B. a data collection circuit, which comprises^

d. a capacitance depending oscillator;

e. a multiplexer for connecting one at a time one of said capacitors to said oscillator! and

f. a processor for controlling said multiplexer to sequentially select one at a time another capacitor from said capacitors, for determining a respective oscillator frequency resulting from each of said selections, and for storing within a memory for each such selection a respective frequency and time stamp, said all storage forms a raw data; and g. memory for storing said raw data.

2. System according to claim 1, wherein each of said ring capacitors comprises a first plate which is made of a foil that surrounds a peripheral portion of said first wall, a dielectric material made by the material of said wall, and a second plate which is formed by the contact area of the urine with said first wall opposite said ring capacitor foil respectively, and wherein said bottom capacitor comprises a first plate which is made of a foil which is disposed at a bottom of said first wall, a dielectric material made by the material of said wall, and a second plate which is formed by the contact area of the urine with said first wall opposite said bottom capacitor foil.

3. System according to claim 2, wherein each of said foils is a conductive foil which is disposed on the external surface of said first wall.

4. System according to claim 1 wherein each of said ring capacitors is separated from adjacent one or more capacitors by a narrow gap respectively.

5. System according to claim 1, wherein each of said narrow gaps has an inclined shape relative to the bottom of the cup.

6. System according to claim 5, wherein each of said inclined narrow gaps has a saw tooth shape.

7. System according to claim 1, wherein each of said ring capacitors comprises a first plate which is made of a foil that is disposed on an internal surface of said first wall, a dielectric material made by the material of urine, and a second plate which is provided over a post at the center of the vessel, and wherein said bottom capacitor comprises a first plate which is made of a foil which is disposed at the bottom of said first wall, a dielectric material made by the material of said wall, and a second plate which is formed by the contact area of the urine with said first wall opposite said bottom capacitor foil.

8. System according to claim 1, wherein said multiplexer, oscillator, processor, and memory are provided within a USB device which is connectable to said vessel via a port, and which is connectable to a computer via a USB port.

9. System according to claim 8, wherein the USB device is connectable to said vessel via a same USB port which is used for connecting the USB device to the computer.

10. System according to claim 1, wherein said data collection circuit is included within the vessel, and wherein the content of said memory is transferred to a computer or smartphone wirelessly.

11. System according to claim 1, wherein the oscillator frequency is inversely proportional to the capacitance of each of said capacitors respectively.

12. System according to claim 1, wherein said vessel further comprises a funnel for directing any additional urine to the bottom of the vessel. -so- is. System according to claim 1, wherein the funnel, internal surface of said wall, or both are coated with a hydrophobic material or made from material with hydrophobic properties.

14. System according to claim 1, wherein said common electrode is placed along the height of the internal surface of said first wall.

15. System according to claim 1, wherein the vessel further comprises a second peripheral wall, and wherein said peripheral wall is covered by a shielding conductive foil connected to a fixed voltage to shield the vessel from the body effects of the user.

16. System according to claim 1, wherein the vessel is cylindrical.

17. System according to claim 1, wherein the vessel has a truncated cone shape.

18. System according to claim 1, for providing a urination and drinking diary, which further comprises buttons for inputting a drinking volume, and wherein the system records each time said drinking and a corresponding time stamp.

19. System according to claim 18, wherein said drinking cup is a cup which is separate from said urination cup.

20. System according to claim 1, wherein the oscillator is replaced by a charging circuit, and wherein the measured urine volume is determined by measuring the period or voltage and rate of charging rather than the frequency determination.

21. System according to claim 2, wherein each of said foils is disposed at the internal surface of said first wall.

22. System according to claim 1, which does not comprise a bottom capacitor.

23. System according to claim 1, wherein each of said ring capacitors comprises a first plate which is made of a foil and a second plate which is also made of a foil placed at a small distance apart, where the urine is the dielectric material.

24. System according to claim 23, wherein the plate structure is located as a post at the center of the vessel.

25. Method for measuring a volume and flow rate of urine, which comprises^ a. providing a vessel;

b. providing at the vessel a bottom capacitor and plurality of ring capacitors, each of said capacitors comprises an external plate, a dielectric material and an internal plate, wherein the area of said internal plate is determined by the volume of urine within the vessel, and by a possible slant orientation of the vessel;

c. providing a capacitance depending oscillator!

d. while giving urine into said vessel, selecting sequentially one at a time one of said capacitors, and connecting the same to said oscillator! and e. during each such selection, recording respectively within a memory the temporal frequency and time stamp of said oscillator! and

f. at the end of said urine giving, analyzing said stored frequencies and respective time stamps in memory to determine the temporal urine volumes and urine flow rate.

26. Method according to claim 25, wherein said analysis comprises^

a. grouping the plurality recorded frequencies and time stamps respectively according to the respective capacitors!

b. determining the progression of the urine flow starting from said bottom capacitor and higher to a highest influenced capacitor from among said ring capacitors, based on said frequencies and time stamps corresponding to each capacitor! and

c. determining a total urine volume based on the highest influenced capacitor, and possibly also based on a calculated slant of the vessel! d. calculating temporal flow rates during said progression based on frequency variations during said progression.

27. Method according to claim 25, wherein the flow rate linearly relates to the rate of _AtAtA^ , wherein is the measured time, and t is a respective time.

28. Method according to claim 25 wherein said bottom capacitor is used to determine the time of beginning of the procedure, and the volume and flow rate of urine at the beginning of the procedure until this capacitor is fully covered.

29. Method according to claim 28, wherein at the beginning of the procedure, when said bottom capacitor is not fully covered with urine, the urine volume is determined by an integration of the volume, as determined with respect to said bottom capacitor, and with respect to one or more of the ring capacitors.

30. Method according to claim 25, wherein one or more gaps between capacitors respectively are taken into account in the analysis.

31. Method according to claim 25, wherein the width of each ring capacitor is selected to relate to a predetermined urine volume, and knowledge of this predetermined volume is used in the analysis.